I believe in the five-second rule.
My two-year old daughter has no concept of this. When she does not want to eat her peas, she at times tosses them on the floor, clearly thinking that she is now rid of THAT problem. How wrong you are, my daughter. This is when I get her with the five-second rule. Ha! Here's your pea once more!
It would seem that God believes in a cosmic five-second rule; He never lets anything go to waste. This is true even when it is us trying to do the wasting. Haman, for example, in the book of Esther attempts to kill God's own people, the Jews - to put to waste people at the center of God's plan in history. Trying something like that on God is like throwing your pea on the floor right in front of dad. Don't try it!
Of course, God picked that pea right up and put it back on the table. He used Haman's plot against him, and instead of Haman gaining greater glory and standing in the empire, the Jewish Esther and Mordecai do. I particularly love how it's not that God goes and gets another pea ("how long can he keep this analogy up?") to replace the ruined one. He uses everything already in play to turn it around for His people.
For those who place their faith in Him, God never lets anything go to waste. Instead, He uses everything - triumphs, failures, blessings, and sufferings - for our good. We simply trust our past, present, and future to Him and watch Him work.
